OECD (2002), „Guidance Document on the Recognition, Assessment and Use of Clinical Signs as Humane Endpoints for Experimental Animals Used in Safety Evaluation“, OECD Environment, Health and Safety Publications (EHS), Series on Testing and Assessment, No. 19, OECD Publishing, Paris.
Iz iskustva je vidljivo i da biološki čimbenici poput rasta i sadržaja lipida u ribi mogu u velikoj mjeri utjecati na rezultate i možda ih treba uzeti u obzir.